how to dynamic count spicific charter words in a string in java code example

Example: how to count words in string in java

String str = "I am happy and why not
  and why are you not happy and you should be";
        String [] arr = str.split(" ");
        Map<String, Integer> map = new HashMap<>();

        for (int i=0 ; i < arr.length ; i++){
                if (!map.containsKey(arr[i])){
                    map.put(arr[i],1);
                } else{
                    map.put(arr[i],map.get(arr[i])+1);
                }
        }
        for(Map.Entry<String, Integer> each : map.entrySet()){

  System.out.println(each.getKey()+" occures " + each.getValue() + " times");
        }